This invention relates to an arrangement for indicating the length of a cable and, more particularly, to such an arrangement wherein only one end of the cable is required to be accessed.
When working with wiring within a building, it is often necessary to know the overall length of a particular cable between its termination at a wiring closet and its remote end. This is particularly true with Type I cable (i.e., shielded twisted pair) when CATV signals are to be transmitted over the cable so that appropriate amplification of the CATV signals can be effected. Since the cable is usually not visible or accessible over its entire length, a physical measurement of the length of the cable is not possible. It is therefore an object of the present invention to provide an arrangement for indicating the length of a cable which does not rely upon the entire cable length being visible and accessible.
It has heretofore been proposed to use cable resistance as an indicator of cable length. However, in order to effectively measure the cable resistance, connections must be made at both ends of the cable. Thus, for a two wire cable, the two wires at the remote end must be connected together and then a resistance measurement is made from the near end. This is disadvantageous in that it requires personnel to travel to the remote end of the cable, identify the specific cable wires, and make the connection. After the resistance measurement is made, the remote ends of the cable wires must be disconnected. It is therefore a more specific object of this invention to provide an arrangement for indicating the cable length while only requiring the cable to be accessed from one end.